<style>
    this {
        font-size: 18px;
    }
    
    this#hello {
        background: green;
    }
    
    h1, h2 {
        color: #c23531;
        text-align: center;
        background: rgba(0, 0, 0, .3);
    }

    @media screen and (max-width: 300px) {
        h1 {
            background-color:lightblue;
        }
    }
    
    @keyframes j-loader {
        0%,
        100% {
            transform: rotateZ(0deg)
        }
        91.66% {
            transform: rotateZ(-30deg)
        }
    }

    @keyframes x-loader {
        from {
            transform: rotateZ(0deg)
        }
        to {
            transform: rotateZ(-30deg)
        }
    }
</style>
<div id="hello">
    <h1>Hello JTaro Module !!!</h1>
</div>